From 8c172dde41db666f7a5f3bb62205da017e23c0ec Mon Sep 17 00:00:00 2001 From: Justin Madru Date: Fri, 18 Dec 2009 15:52:53 -0800 Subject: Staging: s5k3e2fx.c: simplify complexity by factoring the code was looping, setting s_move[i] to the following calculations if (actual_step>= 0) s_move[i] = ((((i + 1) * gain + 0x200) - (i * gain + 0x200)) / 0x400); else s_move[i] = ((((i + 1) * gain - 0x200) - (i * gain - 0x200)) / 0x400); but, this code reduces to the expression s_move[i] = gain>> 10; The reason for the complexity was to generate a step function with integer division and rounding to land on specific values. But these calculations can be simplified to the following code: gain = ((actual_step<< 10) / 5)>> 10; for (i = 0; i<= 4; i++) s_move[i] = gain; Signed-off-by: Justin Madru Reviewed-by: Ray Lee Signed-off-by: Greg Kroah-Hartman --- drivers/staging/dream/camera/s5k3e2fx.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'drivers/staging') diff --git a/drivers/staging/dream/camera/s5k3e2fx.c b/drivers/staging/dream/camera/s5k3e2fx.c index edba19889b0..66582af5a58 100644 --- a/drivers/staging/dream/camera/s5k3e2fx.c +++ b/drivers/staging/dream/camera/s5k3e2fx.c @@ -1093,14 +1093,10 @@ static int32_t s5k3e2fx_move_focus(int direction, int32_t num_steps) actual_step = step_direction * (int16_t)num_steps; pos_offset = init_code + s5k3e2fx_ctrl->curr_lens_pos; - gain = actual_step * 0x400 / 5; + gain = ((actual_step << 10) / 5) >> 10; - for (i = 0; i <= 4; i++) { - if (actual_step >= 0) - s_move[i] = ((((i+1)*gain+0x200) - (i*gain+0x200))/0x400); - else - s_move[i] = ((((i+1)*gain-0x200) - (i*gain-0x200))/0x400); - } + for (i = 0; i <= 4; i++) + s_move[i] = gain; /* Ring Damping Code */ for (i = 0; i <= 4; i++) { -- cgit v1.2.3